Figure 10.

Proposed model of participation of autophagy during T. cruzi metacyclogenesis. In epimastigotes, cruzipain precursors are found in the compartments of the biosynthetic-secretory pathway whereas mature Cz is collected in reservosomes. Autophagy induction during T. cruzi metacyclogenesis promotes the fusion of autophagosomes (possibly derived from acidocalcisomes) to reservosomes. As a result of this interaction, reservosomes turned more acidic and hydrolytic, Cz increases its activity and finally undergo self-proteolysis (Intermediate structure). Newly differentiated metacyclic trypomastigotes displayed Cz in lysosomes and also in vesicles located close to the plasma membrane, a position that is enhanced in starved trypomastigotes. K: kinetoplast, G: Golgi apparatus, ER: endoplasmic reticulum, N: nucleus, R: reservosomes, Au: autophagosomes, Ac: acidocalcisomes, Ly: lysosomes, CV; cruzipain vesicles